Suction-type grain dryer and cooler



March 16, 1948. A. a. WELTY SUCTION-TYPE GRAIN DRYER AND COOLER FiledJune 19,1944 3 Sheets-Sheet 1 fig Paulo March 16, 1948. A. B. WELTYSUCTION-TYPE GRAIN DRYER AND COOLER 3 Sheets-Sheet 2 Filed June 19, 1944March 16,. 1948. A? wELTY 2,437,899

SUCTION-TYPE GRAIN DRYER AND COOLER Filed June 19, '1944 3 Sheets-Sheet3 306%.: I diri fl we'Zfy Patented Mar. 16, 1948 SUCTION -TYPE GRAINDRYER AND COOLER Albert 3. Welty, Moline, lll., asslgnor toInternational Harvester Company, a corporation of New Jersey ApplicationJune 19, 1944, Serial No. 540,967

4 Claims. 1

This invention relates to a new and improved suction-type grain dryerand is a modification of my grain dehydrator application having SerialNo. 528,254, filed March 27, 1944 now Patent No. 2,410,851.

An important object of this invention is to provide for the drying offreshly picked grains by the particular means of drawing heated air upthrough a column of grain.

In my prior grain dehydrator device, I provided a means for blowing airover a furnace and thereupon upwardly through a column of grain to bedried. Numerous problems arose whereby it was necessary to employspecial complex mechanisms in order that the dehydrating device shouldoperate efliciently. It is an object of the present device to overcomethe need for the special mechanisms employed in my previous device, toprovide a grain dryer with a minimum of operating parts, and to stillmaintain the high standard of operating emciency.

Another important object of the present invention is to provide a meansfor drawing air over a furnace and up through a column of grain to bedried.

Another and still further important object is to provide a grain dryerincluding a column of grain and means for drawing heated air in at onelevel of the .column and means for drawing cool air in at another levelof the column.

A still further important object is to provide a suction-type graindryer wherein the supply of heat is completely utilized.

Other and further important obiects ol the present invention will becomeapparent from the disclosures in the following specification andaccompanying drawings, in which:

Figure 1 is a longitudinal sectional view of the grain dryer of thisinvention;

Figure 2 is a sectional view taken on the line 2-2 of Figure 1; and

Figure 3 is an end view of the device as shown in Figures 1 and 2.

As shown in the drawings:

The reference numeral I indicates generally a housing for a grain dryerwhich comprises several units, namely, a. fan housing II, aheatproducing chamber I2. a grain chamber I3, and a cooling chamber I4.

The principle of the present grain dryer is to draw air through theheat-producing chamber up through the grain chamber and thereupondischarge it to the atmosphere. Contrary to my previous device whichforced air through a similar path of travel, the present device employs58 drive through the pulley I8 and belt I9 and fur-- a suction fanwithin housing II for pulling or drawing heated air up through thecolumn of grain to be dried and from there into the fan and dischargedthrough an exhaust conduit I6, as best shown in Figures 1 and 2.

An engine I1 is mounted at one end of the grain dryer housing I0 and isadapted, b means of a pulley I8 and belt I9, to drive the pulley 20which is keyed or otherwise fastened directly to the fan shaft 2 I. Itis evident that the fan. not shown but positioned within the fan housingII, will be driven by the fan shaft 2| and create a suction on a sideopening 22. This opening in the fan housing II communicates with the topof the grain chamber section I3 and is adapted to establish a suctiononthe top of a column of grain within the section I3.

As best shown in Figures 1 and 2, the chamber I3 is surrounded withinsulated walls 23 which prevent the escape of heat used in thegraindrying process. A series of plenum chambers 24, 25, and 26 extendlongitudinally of the chamber I3 and communicate at one end with theheat producing chamber I2, as shown at 21. The upper portions of theside walls of the plenum chambers are equipped with screened apertures28. The suction fan is adapted to draw air through the heat-producingchamber through the passage 21 into the plenum chambers 24, 25, and '26and thereupon up and out through the screened apertures 28.

The heat producing chamber is supplied with a furnace 29 which may beany one of several types, such as oil, gas, coal or the like. Thisfurnace 29 is a sealed unit and exhaust gases are not allowed to escapeinto the heat producin chamber I2 but rather are confined within heatexchange conduits 30, which progress spirally upwardly around thefurnace 29 and communicate with the furnace dome 3| through a conduit32. The heat exchange conduits 30' extend upwardly and include a bank ofheat exchange conduits 33 shown in dash lines in Figure 2. There is nocommunication between the suction opening 22 of the fan and the heatproducing chamber I2 except indirectly through the grain'chamber I3.

The engine I1 is surrounded with a housing 84 which is fastened to thegrain dryer housing I0. An opening 35 is formed in the grain dryerhousing I0 and permits direct communication from the interior of theengine housing 34 to the heat producing chamber I2 of the grain dryer.It is apparent that the longitudinal positioning of the engine I1 isconducive to easy power take-oil 3 ther is conducive to the utilizationof heat created by the engine l1 which complements the heat created bythe iurnace 23 to eflect a drying of the grain. The forward end of theengine Il may be equipped with a radiator or the like, but in any event,there is some opening at the fore end of the engine housing 34 to permitair to be drawn in over the engine I! and back through the housingcommunicating opening 34 and thereupon to progress downwardly over thefurnace dome 3i and around the heat exchange conduits 30 and 33, so thatthe air admitted to the plenum chambers 24, 23, and 23 through thepassage 21 is quite hot. With the suction i'an drawing this hot airupwardly through a column of grain in the chamber i3, this column ofgrain will be dried to enable it to be stored without rear of spoilage.It will be understood, 01 course, that a sealed conduit 33 covers theopening]! in the suction fan housing I! and Joins with the grain chamberl3 through the opening 31. This prevents the fan from short-circuitingthe travel or heated air and makes it impossible for heat to be drawnof! the furnace 23 up to the ian housing IS without first circulating upthrough the grain chamber I3. The arrows indicate the direction of airtravel.

The grain to be dried is put into the hopper 38 whereupon it is raisedfrom the bottom thereof by means of an elevator 33 which carries thegrain upwardly to a point where it discharges into the grain dryer inlethopper 40, as best shown in Figure 1. A centrally located,longitudinally extending worm 4| carries the grain fed to the hopper 40along the entire length oi the grain chamber I3. As best shown in Figure2, the worm 4| is positioned within a trough-like housing 42. Thishousing 42 is equipped with regularly spaced openings 43 on the underside thereof so that the grainmay be discharged downwardly into thechamber I3 along the entire length of the chamber. The grain is adaptedto extend from a point at the bottom of the plenum chamber up to thebottom of the tubular housing 42. Discharge rolls 44 are positionedadjacent the sides of the plenum chambers 24, 2B, and 28, so that thecolumn of grain moves continuously downwardly and the dried graindischarges at the bottom. The discharge rolls 44 are equipped withalternate intermittent slots 45 within which the grain deposits, and asthe rolls rotate, the deposited grain is discharged into the coolingcompartment i4 whereupon a worm 43 extending lengthwise of thecompartment will carry the grain to a discharge elevator 41, as bestshown in Figure 3, whereupon the dried and cooled grain is elevated anddischarged through either of two spouts 48 and 43. The trough-like framestructure 50 adjacent the discharge rolls 44 is so designed that thegrain descending within the'chamber i3 is concentrated on one portion orthe rolls, in order that the grain pockets or slots 45 may be filled onthe upper side and may be discharged into the compartment i4 as therolls 44 rotate.

The compartment i4 .is termed a cooling chamber, for the reason that itassists in brlngingthe heated grain down to normal temperatures beforeit is removed from the dryer and stored. There is the possibility thatstoring of grain of very high temperatures will cause moisture to becondensed thereon. The bottom of the cooling compartment i4 is opened tothe atmosphere through chamber l3, but rather they are designed topermit atmospheric air at room temperature to be drawn in through thepassages 5i and 42 up around the loose-fitting discharge rolls 44 and upthrough the column of grain by reason of the suction created by the fan.of course, this will tend to reduce the temperature of the heated air asthe cool room-temperature air combines with the heated air at the plenumchamber outlets 23, but this is not detrimental to the effectiveoperation of the machine. The suction fan draws hot air into the chamberi3 at the level defined by the plenum chamber outlets 23 and draws coolair into the chamber I3 at the level defined by the discharge rolls 44which is below the level of the hot air entrance. As the grain to bedried descends within the compartment [3, its temperature increasesuntil it reaches the hot air openings 23 in the plenum chambers, andafter passing that point, the cool room-temperature air acts on thegrain to reduce its temperature so that, in fact, the cooling chamberbegins immediately below the openings 23 in the plenum chambers. Coolingcontinues as the grain discharges downwardly through the rolls 44 and asit falls down the inclined V-shaped bottom 53 of the cooling compartmentI4.

The exhaust furnace gases are more completely utilized by extending thebank of heat exchange conduits 33 around the fan to a vertical conduit54, which communicates with the longitudinally extending conduit 35buried within the column of grain within the compartment l3. Thisconduit 55 does not extend completely to the end of the housing I0 butrather falls short and permits the exhaust gases to pass outwardly intoa superimposed housing 53 and thereupon is directed back through theouter housing 58 and thence discharged through the suction fan. It ispossible that some of these exhaust gases will condense within thishousing 53, and for that reason a drain 53' is provided at the endthereof and extends through the housing i0. It is necessary to supplythe exhaust gases with some suction to maintain a continual flow of thegases, and in order to effect this suction, a valve gate 51 in the outerhousing 86 and communicating with the suction fan, shownin Figures 1 and2, may be adjusted at any degree of opening to obtain greater or lesssuction as necessary. The position of the gate 51 is such that theexhaust gases are above the column ofgrain and pass directly to the fanrather than proceeding down into the grain and thus contaminating it.The particular valve gate shown has an operating handle 53 extending outthrough the housing ID in order that the opening of the gate 51 may beadjusted. It is, of course, obvious that the valve may be any one ofseveral types such as a sliding valve or some other suitable type.

Drive for the worms 4| and 46 and the discharge rolls 40 is taken fromthe tan driving shaft 2! by means of the pulley 58, belt 60, and apulley Bimounted on a shaft 62. An idler pulley 83 is adapted to heangularly adjustably positioned so that the tension of the belt may befixed as desired. The pulley 63 may be moved away from the belt to causethe belt to completely disengage from the pulley 59, thus acting as aclutch to stop motion of pulley Si and shaft 62. The shaft 62 extendsrearwardly of the grain dryer. housing I 0 and has mounted thereon asmall gear 64 which engages the gear 65 keyed or otherwise fastened tothe shaft 63 of the worm 4|. The drive for the discharge rolls 44 andthe worm 48 is taken from a rear extension 81 of the shaft 88. Mountedon this rear extension 81 is a pulley 88. The discharge rolls 44 haverearwardly extending shafts 89, the outer ends of which supportsprockets 18.

It is a requirement oi this grain dryer that the discharge rolls 44rotate very slowly, and to effect that result the particular drive asindicated in Figure 3 is employed. The pulley 88 is equipped with acrank pin 1| to which is attached a pitman 12. It will be evident thatas the pulley 68 rotates, the pitman 12 will reciprocate vertically. Thelower end of the pitman is attached at 18 to an arm 14 which is pivotedon a shaft 15. A ratchet wheel 18 is mounted on this shaft 15 andcarries with it a sprocket 11 in a common plane with the sprockets 10.The arm 14 is equipped with a projection 18 to which is-pivoted a awl 19for engagement with the ratchet wheel 18. As the pitman I2 is liftedupwardly, the pawl 19 engaging the ratchet teeth causes the ratchetwheel 18 to rotate in a clockwise direction as viewed in the device ofFigure 3. The effective movement of the pawl 18 may be curtailed by themember 88. This member 88 is in the form of a circular segment and ispivoted on the shaft The vertex 8| of the segment 80 is adjustablypositioned within the slotted bracket 82. The outer arcuate end of thesegment 88 is adapted to coincide with the arcuate periphery of theratchet wheel 18. The pawl 18, as shown in Figure 3, is thus preventedfrom contacting the ratchet teeth, and movement of the ratchet wheel 16is thereby delayed until the pawl 19 passes beyond the upper limit ofthe segment 80. The segment 88 may be pivoted about its center 15 andfixed in any desired position within the slotted bracket 11 to eiiectany rate of ratchet rotation that is permissible between the limits ofmovement of the pitman 12. A second pawl 83 is resiliently held againstthe bottom of the ratchet wheel 18 by means of a spring 8t. This ratchetwheel prevents rearward or counterclockwise rotation of thetratchetwheel 18 when the pawl 19 no longer is engaged with the ratchet teeth. Achain 85 is wrapped around each of the sprockets as well as the drivesprocket 11, an idler sprocket 88, and the sprocket 81. The sprocket 81is mounted on a stub-shaft 88 and acts as an idler sprocket in order tosecure the 6 e drawing of hot air in at one level of the grain and asimultaneous drawing in of cooler air at a lower level of the graincontributes to an efllcient operating system. The entire system isgreatly facilitated in its efllciency by a complete use of exhaust gasesby means of a plurality of heat transfer conduits. It is foreseeablethat combustion may eventually be so complete that exhaust gases may bemixed with warm air in proper direction of rotation of the sprockets 10driving the discharge rolls M.

The upper end of the intake elevator is equipped with a pulley 89mounted on a shaft 90 which extends within the elevator and drives theelevator flighting. A similar pulley 8| is mounted at the top of thedischarge elevator 41 on a shaft 92. A further pulley 83 is mounted on astub-shaft 9i and is in the same plane with the pulleys 88, 88, and M. Abelt 85 encircles these pulleys in the manner shown wherein the smallpulley 93 acts as an idler. It is evident from this arrangement ofpulleys and belt 88 that drive is imparted from the pulley 88 to theelevators 38 and 41. The driving of the elevator 41 causes a driving ofthe worm 48 which carries the grain from the cooling chamber to thedischarge elevator. A second pulley 88 is fastened to the shaft 92 andis adapted to drive a moisture testing device 91 operable by means ofthe pulley 88. An idler pulley 98 is mounted on a stub-shaft I08 afllxedto the housing 88.

The novel cooling method employed in this grain dryer is believed to bequite distinct from any cooling method heretofore employed. The

the direct drying of'the grain without fear of any contamination. Thiswould, of course, result in a simpler and more economic machine. Infurtherance of the system emciency, the incoming air is preheated by theengine I! as heretofore described. However, if the quantity of air takenin over the engine [1 is insufficient to satisfy the demand of thedryer, an opening may be employed in the side wall of the device at apoint above the furnace which will augment the supply of air taken inthrough the engine.

What is claimed is:

1. A grain dehydrator having an insulated housing comprising an engine,a vertical grain chamber, an auger for feeding grain along the top ofsaid grain chamber, graindlscharge rolls at the bottom of said grainchamber, said auger and discharge rolls rotatably driven by said engine,a heating plant requiring a supply of air, an air intake positioned oversaid engine, whereby air utilized by the heating plant is preheated, acommunicating passage between the heating plant and the grain chamber,and suction means for drawing air in over the engine, through theheating plant and up through the grain chamber, said grain chamberhaving an auxiliary air entrance located beneath the discharge rolls andbypassing the heating plant and entering said grain chamber at a levelbeneath the level of the entrance of the hot air communicating passageand whereby the suction means draws cool air up from the auxiliary airentrance around the discharge rolls to mingle with the heated air in thelower portion of the grain chamber.

2. A grain dryer having a housing including a heating plant having anair inlet and a hot air outlet, said heating plant having its gases ofcombustion maintained separately from said air inlet and outlet, a grainchamber, a communicating passage between said hot air outlet and saidgrain chamber, heat exchange conduits carrying the gases of combustionaround the air inlet and through a longitudinally extending sealedcompartment within said grain chamber, said sealed compartment having aport providing communication between the compartment and the top of thegrain chamber, valve means in the port for regulating passage of exhaustcombustion gases, and a suction fan at the top of said grain chamberdrawing air into and through the heating I plant, through the grainchamber and out a discharge through the suction fan and drawing outexhaust combustion gases in an amount dependent upon the position of thevalve means.

3. In a grain dryer having a housing including a vertical grain chamber,means for heating and cooling grain in said chamber, said grain chamberhaving an opening intermediate the top and bottom for the entrance ofhot air, and said grain chamber having an opening in the bottom thereoffor the entrance of cool air, suction means on the top of the grainchamber for drawing both hot and cool air upwardly through the grain,

whereby the cool air at the bottom of the grain chamber above theopening for the hot air, means for moving grain downwardly through saidgrain chamber, a grain discharge at the bottom of the grain chamberwhereby grain originally heated at the top is cooled before beingdischarged, said discharge including a plurality of rolls having spacedpockets adapted to receive a quantity of grain and upon rotation 01' therolls to empty the grain beneath the. grain chamber, a housing structureadjacent the rolls providing sufllcient space for passage of air, and aV-shaped bottom for said grain chamber, said cool entrance openinglocated in the sides of the V-shaped bottom in a manner to permit grainemptied from the pockets of all the rolls to flow down over the openingto the apex of the V-sh'aped receptacle.

4. In a grain dryer having a housing including a vertical grain chamber,means for heatin and cooling grain in saidv chamber, said grain chamberhaving an opening intermediate the top and bottom for the entrance ofhot air, and said grain chamber having an opening in the bottom thereoffor the entrance of cool air, suction means on the top of the grainchamber for drawing both hot and cool air upwardly through said grainchamber, whereby the cool air at the bottom of the grain chamber coolsthe grain therein and the hot air tempered by the cool air heats thegrain in the chamber above theopening for the hot air, a grain dischargeat the bottom of the grain chamber whereby grain originally heated atthe top is cooled before being discharged, said discharge including aplurality of rolls having 8 spaced pockets adapted to receive a quantityof grain and upon rotation of the rolls to empty the grain beneath thegrain chamber, a housing structure adjacent the rolls providingsufllcient space for passage of. air, a V-shaped receptacle beneath saidgrain chamber whereby the grain emptied from the pockets of all therolls will flow down to the apex of the V-shaped receptacle, and alongitudinally extending worm within the apex of the receptacle formoving the grain to one end thereof.

ALBERT B. WELTY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS France Oct. 10, 1922

